1. Field of the Invention
The present invention relates to a refrigeration system which comprises compressing means, condensing and receiving means and an evaporator, each having an inlet and an outlet; and a separator having an inlet and a first and a second outlet.
More particularly, the present invention is directed to a refrigeration system having an overfed evaporator, i.e. an evaporator that is fed with a liquid refrigerant in such a rate that the refrigerant is not totally evaporated at the outlet of the evaporator.
The invention also relates to a small volume separator for use in such a refrigeration system.
2. Background of the Invention
In such a conventional overfed refrigeration system, a large volume separator, often combined with a refrigerant pump, is used and is connected by long pipes with the evaporator for feeding the separated liquid refrigerant to the inlet of the evaporator and for receiving the liquid and vapor refrigerant from the outlet of the evaporator, one outlet of the separator being connected to the inlet of the compressing means for feeding the separated vapor refrigerant gas thereto. Therefore, the total volume of the refrigerant in the conventional system is large in comparison to the volume of the refrigerant maximally evaporated in the evaporator.
Also, the pressure losses are large in the conventional system which makes it difficult to attain as low a temperature as otherwise would be possible in the evaporator and requires the use of a higher capacity compressor. Further, a pump is normally necessary for transporting the liquid refrigerant to the evaporator which pump easily will be exposed to cavitation as a consequence of the low temperatures of the refrigerant and load fluctuations. Lowering these temperatures further would increase the risk of cavitation in the pump and also result in increased pressure losses in wet return suction lines.